1. Field of the Invention
This invention relates to load support structural members, particularly suitable for use with motor vehicles.
2. Description of the Prior Art
Load support structural members, particularly for use with motor vehicles, conventionally have left and right one-piece C-channel side support members with cross members connecting the two side members together. Brackets are welded onto each C-channel side member for connection with wheel suspension assemblies and a vehicle body. The conventional frame member comprises a significant proportion of the total weight of the vehicle. The conventional frame has excessive weight due to the thickness of the C-channel side members and the massive brackets welded thereon for attachment to the wheel assemblies. The excess weight of the frame cuts down on fuel efficiency of the motor vehicle. In addition, the energy needed in the refining and manufacture of the excess metal can be conserved if the excess metal is removed from the frame.
Federal regulations controlling fuel economy of motor vehicles, including trucks, have highlighted the need to make high strength frames with a minimum amount of weight. Attempts have been made to make a fabricated frame which deviates from the conventional frame having C-channel side members and cross members. One such frame is disclosed in U.S. Pat. No. 3,940,162 issued to Winslow et al on Feb. 24, 1976. The Winslow et al reference discloses side members having a top and bottom plate, each plate spaced apart with a reinforcing web zigzagging back and forth between the two plates. The web has a surface area which forms varying oblique and acute angles with the respective top and bottom plate members. Cross members are welded to the side members.
Frames often undergo high stresses at particular points. It is known that one high stress area is where the frame is connected to the wheel assemblies. Commonly, the wheel assembly is connected to the frame through a leaf spring suspension system at one or two mountings on the frame. These mounting areas are subject to the very high stresses of the driving force exerted by the drive wheels in either forward or reverse gear. Due to the lighter weight of the frames, the stress exerted on the frame must be more evenly distributed. A frame to alleviate this excessive stress at these points is desirable.